Asolution of ammonia and water contains 3.10×1025 water molecules and 7.10×1024 ammonia molecules. how many total hydrogen atoms are in this solution?

They can measure  the amount of energy gained or lost

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .